Wide Variability in Caloric Density of Expressed Human Milk Can Lead to Major Underestimation or Overestimation of Nutrient Content

Abstract

BACKGROUND: Very-low-birth-weight infants continue to face significant difficulties with postnatal growth. Human milk is the optimal form of nutrition for infants but may exhibit variation in nutrient content. OBJECTIVE: This study aimed to perform macronutrient analysis on expressed human milk from mothers whose babies are hospitalized in the neonatal intensive care unit. METHODS: Up to five human milk samples per participant were analyzed for protein, carbohydrate, and fat content using reference chemical analyses (Kjeldahl for protein, high pressure liquid chromatography for carbohydrates, and Mojonnier for fat). Calorie content was calculated. RESULTS: A total of 64 samples from 24 participants was analyzed. Wide variability was found in calorie, protein, carbohydrate, and fat composition. The authors found an average of 17.9 kcal/ounce, with only 34% of samples falling within 10% of the expected caloric density. CONCLUSION: The assumption that human milk contains 20 kcal/ounce is no longer supported based on this study. This supports promoting an individualized nutrition strategy as a crucial aspect to optimal nutrition.